Meatballs are treacherous territory. They're so simple in concept and design, but that simplicity does not mean they are easy to get right. Meatballs a true comfort food, but they can be mealy, dry, crumbly, or just plain bland.
Here's a time tested recipe that goes great alone or with pasta:
1 shot of Rum (consume)
2 lbs of Leanest Hamburger/ Buffalo
1 lb fresh Mozzarella
1 lb shredded Mozzarella
1 cup Bread Crumbs
1-2 Quarts Red Tomato Sauce (Homemade if possible)
First, drink yourself some rum. In a large bowl add the hamburger, the breadcrumbs, and the eggs. The bread and the eggs will form a binder to keep the meatballs from breaking apart. With clean hands, knead the crumbs and egg together. Then add the diced garlic, onion, basil, oregano, as well as salt and pepper to taste. I would recommend adding a little bit of the seasoning at a time and knead repeatedly to ensure even coating. Once the meat is prepared set it aside and get out your cutting board.
Slice the mozarella into 1/2 to 3/4 inch cubes and set aside.
Roll the meat mixture into a ball with the cheese cube in the center. As they cook the cheese melts, preventing the lean beef from drying out or becoming grainy.
Now we have a few cooking options. You could pan fry them or slow cook them for several hours in a pasta sauce, but my favorite is to bake them.
For the sake of consistency I'll outline all three.
Grease a pan with olive oil and add the meatballs in one at a time. They will sear to a golden brown on one side and constantly turn them. With this method it is impossible for them to retain their circular ball shape so what you end up with are meat cubes. They taste the same so it really doesn't matter. When the cheese starts to bubble out of the centers into the pan, that's when you know they are done.
Slow cooking in sauce:
Whip up some pasta sauce. When I have the time I like to start with tomatoes and make everything from scratch, but sometimes that isn't an option. I promise not to tell anyone if you use store bought pasta sauce. Put the sauce in a large sauce pan (you see what I did there?) and bring to a low simmer. Pan sear the meatballs quickly on all sides and place in the sauce. Cook for several hours. You can also use a crock pot. This really infuses the juices of the tomato into the overall flavor.
Pasta sauce use:
I have also noticed that using pasta sauce as a cooking medium extracts much of the fats and oils from the meat and causes the sauce to become greasy. I've used it anyway and put it on pasta with the meatballs and had little trouble, but I would recommend keeping a pot simmering on the stove of additional sauce to use with pasta.